Revert of Makes change_id unsigned

mojo/services/view_manager/root_node_manager.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "mojo/services/view_manager/root_node_manager.h"
 
 #include "base/logging.h"
 #include "mojo/services/view_manager/view_manager_connection.h"
 
 namespace mojo {
 namespace services {
 namespace view_manager {
 namespace {
 
 // Id for the root node.
 const uint16_t kRootId = 1;
 
 }  // namespace
 
 RootNodeManager::ScopedChange::ScopedChange(ViewManagerConnection* connection,
                                             RootNodeManager* root,
-                                            ChangeId change_id)
+                                            int32_t change_id)
     : root_(root) {
   root_->PrepareForChange(connection, change_id);
 }
 
 RootNodeManager::ScopedChange::~ScopedChange() {
   root_->FinishChange();
 }
 
 RootNodeManager::RootNodeManager()
     : next_connection_id_(1),
@@ skipping 33 matching lines @@
 View* RootNodeManager::GetView(const ViewId& id) {
   ConnectionMap::iterator i = connection_map_.find(id.connection_id);
   return i == connection_map_.end() ? NULL : i->second->GetView(id);
 }
 
 void RootNodeManager::NotifyNodeHierarchyChanged(const NodeId& node,
                                                  const NodeId& new_parent,
                                                  const NodeId& old_parent) {
   for (ConnectionMap::iterator i = connection_map_.begin();
        i != connection_map_.end(); ++i) {
-    const ChangeId change_id = (change_ && i->first == change_->connection_id) ?
+    const int32_t change_id = (change_ && i->first == change_->connection_id) ?
         change_->change_id : 0;
     i->second->NotifyNodeHierarchyChanged(
         node, new_parent, old_parent, change_id);
   }
 }
 
 void RootNodeManager::NotifyNodeViewReplaced(const NodeId& node,
                                             const ViewId& new_view_id,
                                             const ViewId& old_view_id) {
   // TODO(sky): make a macro for this.
   for (ConnectionMap::iterator i = connection_map_.begin();
        i != connection_map_.end(); ++i) {
-    const ChangeId change_id = (change_ && i->first == change_->connection_id) ?
+    const int32_t change_id = (change_ && i->first == change_->connection_id) ?
         change_->change_id : 0;
     i->second->NotifyNodeViewReplaced(node, new_view_id, old_view_id,
                                       change_id);
   }
 }
 
 void RootNodeManager::PrepareForChange(ViewManagerConnection* connection,
-                                       ChangeId change_id) {
+                                       int32_t change_id) {
   DCHECK(!change_.get());  // Should only ever have one change in flight.
   change_.reset(new Change(connection->id(), change_id));
 }
 
 void RootNodeManager::FinishChange() {
   DCHECK(change_.get());  // PrepareForChange/FinishChange should be balanced.
   change_.reset();
 }
 
 void RootNodeManager::OnCreated() {
@@ skipping 18 matching lines @@
 
 void RootNodeManager::OnNodeViewReplaced(const NodeId& node,
                                          const ViewId& new_view_id,
                                          const ViewId& old_view_id) {
   NotifyNodeViewReplaced(node, new_view_id, old_view_id);
 }
 
 }  // namespace view_manager
 }  // namespace services
 }  // namespace mojo